''Ussurites'' is an extinct ammonoid cephalopod genus belonging to the suborder

Phylloceratina The Phylloceratina comprise a suborder (biology), suborder of Ammonoidea, ammonoid cephalopods, belonging to the Ammonitida, whose range extends from the Lower Triassic to the Upper Cretaceous. Shells of the Phylloceratina are generally smooth w ...

and is included in the family

Ussuritidae Ussuritidae are ancestral, Triassic, Phylloceratina characterized by generally smooth, discoidal, evolute shells with rounded venters and little or no ornamentation and by sutures with primitive monophyllitic saddles with a single terminal branch ...

. Its range is restricted to the early Middle Triassic, (

Anisian In the geologic timescale, the Anisian is the lower stage (stratigraphy), stage or earliest geologic age, age of the Middle Triassic series (stratigraphy), series or geologic epoch, epoch and lasted from million years ago until million years ag ...

) As with the family, the shell of ''Ussurites'' is discoidal, evolute, and generally smooth. The suture is phylletic with divided lobes and simple, rounded, elongate saddles. The ventral lobe is bifurcated, the two branches sharply serrated. The two lateral lobes are asymmetrically trifurcated, sections sharply pointed. The first lateral saddle (closest to the venter) is fairly evenly rounded, the second and third are narrower and asymmetric, leaning away from the venter and toward the umbilicus. '' Monophyllites'', which extends through the Middle Triassic into the

Carnian The Carnian (less commonly, Karnian) is the lowermost stage (stratigraphy), stage of the Upper Triassic series (stratigraphy), Series (or earliest age (geology), age of the Late Triassic Epoch (reference date), Epoch). It lasted from 237 to 227.3 ...

is similar, differing in the details of the suture.

References

* Arkell ''et al.'', 1957. Mesozoic Ammonoides;

Treatise on Invertebrate Paleontology The ''Treatise on Invertebrate Paleontology,'' published from 1953–2007 by the Geological Society of America and the University of Kansas, then 2009–present by the University of Kansas Paleontological Institute, is a definitive multi-authore ...

, Part L (Ammonoidea). Geol Soc of America and Univ Kansas Press. p. L185-186. Triassic ammonites Ammonitida Fossils of Svalbard Anisian life {{Svalbard-stub